Ventilation arrangement

Abstract

A housing for a ventilation arrangement, with a profiled rod providing a radial extension in each corner, with a pivotted guide vane extending between the rod and the remainder of the housing. In normal wind conditions this radial extension guides air into or out of the housing. In very high wind conditions the guide vane can however pivot and/or flex to release any excessive pressure caused by the high wind.

The invention claimed is: 
     
       1. A ventilation arrangement for ventilating a building interior, the ventilation arrangement comprising:
 an air duct which extends in use from roof level into the interior of the building to be ventilated to convey air between an exterior and the interior of the building; 
 a housing locatable on the roof of the building, with ventilation openings provided around a perimeter of the housing to direct moving air caused by wind movement into or out of an upper part of the air duct; and 
 a plurality of guide vanes spaced around the housing and extending outwardly from the housing to guide air into the housing, each of the plurality of guide vanes being mounted to only one of a first inner part of the housing or a respective second part of the housing and extending between the first inner part and the second part, the second part comprising an elongate vertically extending part which defines an elongate gap between the second part and a remainder of the housing, 
 wherein the elongate gap in normal wind conditions is at least substantially closed by a respective guide vane, the guide vanes being flexible so as to flex in high wind conditions to relieve pressure on a windward side of the housing, the windward side of the housing comprising an outside surface of the housing. 
 
     
     
       2. A ventilation arrangement according to  claim 1 , in which the plurality of guide vanes extend substantially radially from the housing. 
     
     
       3. A ventilation arrangement according to  claim 1 , in which the plurality of guide vanes comprise elongate members running substantially vertically. 
     
     
       4. A ventilation arrangement according to  claim 3 , in which the elongate members are in the form of strips of material. 
     
     
       5. A ventilation arrangement according to  claim 1 , in which the plurality of guide vanes are made of a flexible material. 
     
     
       6. A ventilation arrangement according to  claim 5 , in which the plurality of guide vanes are made of rubber or a plastics material. 
     
     
       7. A ventilation arrangement according to  claim 1 , in which each of the plurality of guide vanes is mounted to the first inner part of the housing. 
     
     
       8. A ventilation arrangement according to  claim 1 , in which the arrangement is configured such that in high wind conditions a respective guide vane can be moved by the wind to open the elongate gap. 
     
     
       9. A ventilation arrangement according to  claim 1 , in which the housing is substantially square in plan view, and a guide vane of the plurality of guide vanes is provided at each corner of the housing. 
     
     
       10. A ventilation arrangement according to  claim 9 , in which the plurality of guide vanes extend at a horizontal inclination of substantially 135° to sides of the housing.